U.S. patent application number 12/688333 was filed with the patent office on 2010-05-13 for dishwashing composition with particles.
This patent application is currently assigned to CONOPCO, INC., D/B/A UNILEVER, CONOPCO, INC., D/B/A UNILEVER. Invention is credited to Naresh Dhirajlal Ghatlia, Natasha Pfeiffer, Isaac Israel Secemski.
Application Number | 20100120650 12/688333 |
Document ID | / |
Family ID | 25202554 |
Filed Date | 2010-05-13 |
United States Patent
Application |
20100120650 |
Kind Code |
A1 |
Pfeiffer; Natasha ; et
al. |
May 13, 2010 |
Dishwashing Composition with Particles
Abstract
This invention is directed to a water soluble sachet comprising
a detergent composition having a discrete particle that enhances
cleaning in a dishwashing machine. The water soluble sachet
unexpectedly results in excellent cleaning properties and minimizes
spot and film formation on items being cleaned in a dishwasher.
Inventors: |
Pfeiffer; Natasha;
(Stamford, CT) ; Ghatlia; Naresh Dhirajlal;
(Southbury, CT) ; Secemski; Isaac Israel;
(Teaneck, NJ) |
Correspondence
Address: |
UNILEVER PATENT GROUP
800 SYLVAN AVENUE, AG West S. Wing
ENGLEWOOD CLIFFS
NJ
07632-3100
US
|
Assignee: |
CONOPCO, INC., D/B/A
UNILEVER
Englewood Cliffs
NJ
|
Family ID: |
25202554 |
Appl. No.: |
12/688333 |
Filed: |
January 15, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10266364 |
Oct 8, 2002 |
7674761 |
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12688333 |
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09809942 |
Mar 16, 2001 |
6492312 |
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10266364 |
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Current U.S.
Class: |
510/221 |
Current CPC
Class: |
C11D 17/044 20130101;
C11D 3/3773 20130101; C11D 3/3765 20130101; C11D 17/003
20130101 |
Class at
Publication: |
510/221 |
International
Class: |
C11D 17/00 20060101
C11D017/00 |
Claims
1-21. (canceled)
22. A water soluble sachet comprising a dishwashing composition
wherein the dishwashing composition is a gel comprising discrete
particles having an approximate diameter from about 100 to about
5,000 microns, the sachet suitable for use in a dishwashing machine
having a washing cycle from about 10 minutes to about 60 minutes at
a water temperature from about 40.degree. C. to about 70.degree.
C.
23. The water soluble sachet comprising a dishwashing composition
according to claim 22 wherein the sachet can be used to clean glass
and substantially reduce film.
24. The water soluble sachet comprising a dishwashing composition
according to claim 22 wherein the particle is an anti-foaming
agent, bleach, anti-tarnishing agent, enzyme or a mixture
thereof.
25. The water soluble sachet comprising a dishwashing composition
according to claim 22 wherein the sachet comprising a dishwashing
composition reduces carbonate scale formation on dishware.
26. The water soluble sachet comprising a dishwashing composition
according to claim 22 wherein the sachet comprising a dishwashing
composition further comprises a colorant.
27. The water soluble sachet comprising a dishwashing composition
according to claim 22 wherein the sachet comprising a dishwashing
composition is a unit dose for a dishwashing machine.
Description
FIELD OF THE INVENTION
[0001] This invention is directed to a composition for use in a
dishwashing machine. More particularly, the invention is directed
to a water soluble sachet comprising such a dishwashing composition
along with a discrete particle that enhances cleaning in a
dishwashing machine. The dishwashing composition preferably is a
gel that comprises an anti-spotting agent and at least one of a
water soluble polymer that reduces phosphate scale formation and a
compound that reduces carbonate scale formation. The sachet
unexpectedly results in excellent cleaning properties and excellent
glass appearance without leaving a detergent residue, which is
typically characteristic of dishwashing compositions in tablet or
powder form.
BACKGROUND OF THE INVENTION
[0002] Dishwashing compositions constitute a generally recognized
distinct class of detergent compositions, particularly when
compared to detergents designed for fabric washing. For example,
the ultimate dishwashing composition results in a spotless and
film-free appearance on glassware and silverware after a cleaning
cycle in a dishwashing machine. In fabric washing operations, on
the other hand, detergent compositions which result in greasy, oily
or soapy residues on items that were cleaned can be tolerated.
[0003] Often, washing articles in a commercially available
dishwashing machine entails using three products. Salt is added to
the salt compartment to recharge the ion exchanger which softens
the water, a dishwashing formulation is used to clean the articles
and a rinse aid is used to ensure that the articles are rinsed with
no streaks or smears. Consumers generally find it very
inconvenient, however, to replace or refill such products.
[0004] In order to provide convenient products to consumers,
manufacturers have been making dishwashing tablets in order to
eliminate detergent handling and dosing issues. Such tablets often
have a detergent portion, and a wax portion which contains a rinse
aid. These types of tablets, which are sometimes referred to as
2-in-1 tablets, have disadvantages since they may only be used in a
wash cycle that does not exceed 55.degree. C. This is true because
the wax portion which contains the rinse aid will completely
dissolve in a wash cycle that exceeds 55.degree. C. This causes all
of the rinse aid to drain out of the dishwashing machine before the
actual rinse cycle. Furthermore, such 2-in-1 tablets require that
salt be added to the dishwashing machine in order to obtain optimal
results, and they are very complicated and expensive to
produce.
[0005] Other types of tablets that are well known are often
referred to as pH sensitive 2-in-1 tablets. These types of tablets
have a detergent portion and rinse aid portion that is contained in
a pH sensitive material, the rinse aid portion to be released under
the lower pH conditions of the rinse cycle. The pH sensitive 2-in-1
tablets may be used in wash cycles that exceed 55.degree. C., but
they are known to prematurely release rinse aid in hot washes that
run long. Also, like the detergent tablets with the wax portion,
the pH sensitive 2-in-1 tablets require that salt be added to the
dishwashing machine in order to obtain optimal cleaning results and
they are extremely expensive to produce.
[0006] In addition to the above-described deficiencies of
conventional tablets, such conventional tablets also are known to
characteristically leave residue on dishware being cleaned because
they do not always completely dissolve within a dishwashing cycle.
Conventional tablets are also difficult to handle because they
often require unwrapping before use. Also, those that are not
wrapped can be unpleasant to handle because of fines on the surface
of the tablet.
[0007] It is of increasing interest to provide a dishwashing
composition that works well at all wash temperatures of a
dishwashing system (even temperatures greater than 55.degree. C.),
provides anti-scaling benefits in a system that is high in
phosphate and/or carbonate content (in hard water), does result in
excellent cleaning benefits in water that has not been subjected to
conventional water softening additives (i.e., hard water), provides
a shiny glassware appearance in the absence of conventional rinse
aid compositions and does not leave residue on dishware being
cleaned. This invention, therefore, is directed to a dishwashing
composition that is associated with an anti-spotting agent, and
preferably has at least one of a water soluble polymer that reduces
phosphate scale formation and a compound that reduces carbonate
scale formation on glassware being cleaned. The dishwashing
composition is superior in that it unexpectedly results in
excellent cleaning properties and reduced spotting and scale
formation, even when no salt is added to the dishwashing machine to
soften hard water, when washing cycles exceed a temperature of
55.degree. C., and when no rinse aid composition is added to the
dishwashing machine. In fact, the present invention is directed to
a superior 3-in-1 detergent composition that is contained in a
stable water soluble sachet. Such a superior detergent composition
unexpectedly results in a reduction in film and spot formation even
when compared to similar compositions in solid (e.g.,
powder/tablet) form.
Additional Information
[0008] Efforts have been made to prepare dishwashing compositions.
In U.S. Pat. No. 5,939,373, an automatic dishwashing detergent
composition comprising a phosphate builder and a metal containing
bleach catalyst is described.
[0009] Still other efforts have been disclosed for making
dishwashing compositions. In WO 00/06688, a dishwashing composition
with a coated core is described. The coated core has a substance
that exerts its function in a clear rinse cycle.
[0010] Even further, other efforts have been disclosed for making
dishwashing compositions. In DE 197 27 073 A1, coated detergent
components are described.
[0011] None of the material above describes a dishwashing
composition within a water soluble sachet wherein the dishwashing
composition is in the form of a gel and comprises an anti-spotting
agent. Moreover, none of the material above describes a dishwashing
composition within a water soluble sachet comprising an
anti-spotting agent and a water soluble polymer that reduces
phosphate scale formation and/or a compound that reduces carbonate
scale formation wherein the dishwashing composition results in
excellent cleaning properties and glass appearance when used, for
example, in the presence of hard water, in the absence of rinse aid
compositions and in a washing cycle that exceeds a temperature of
55.degree. C.
SUMMARY OF THE INVENTION
[0012] In a first embodiment, the present invention is directed to
a water soluble sachet comprising a dishwashing composition wherein
the dishwashing composition is a gel which comprises discrete
particles, the discrete particles having an approximate diameter
from about 100 to about 5000 microns, and the discrete particles
and gel being in a particle to gel weight ratio from about 0.005 to
0.4:1.
[0013] In a second embodiment, the present invention is directed to
a water soluble sachet comprising a dishwashing composition having:
[0014] (a) an anti-spotting agent comprising a hydrophobically
modified polycarboxylic acid, a surfactant having a cloud point in
water of less than about 60.degree. C., or both; and [0015] (b) a
water soluble polymer that reduces phosphate scale formation, a
compound that reduces carbonate scale formation, or both wherein
the dishwashing composition is a gel.
[0016] In a third embodiment, the present invention is directed to
a method for minimizing spotting and phosphate and/or carbonate
scale formation on glassware being cleaned, comprising the steps
of: [0017] (a) inserting a water soluble sachet into a dishwashing
machine; [0018] (b) allowing the water soluble sachet to dissolve;
and [0019] (c) subjecting the glassware to a dishwashing
composition comprising the above-described anti-spotting agent, and
a water soluble polymer that reduces phosphate scale formation, a
compound that reduces carbonate scale formation, or both.
[0020] In a fourth embodiment, the present invention is directed to
a package comprising the dishwashing composition described in the
first aspect of this invention and instructions not to use a rinse
aid composition or conventional water softening salts or both.
[0021] As used herein, glassware is defined to include drinking
glasses, and any other articles typically found in a commercial or
domestic dishwasher. Also, as used herein, water soluble sachet is
defined to mean a sachet made of a material that will dissolve, for
example, in a cleaning cycle of a domestic dishwasher. Gel, as used
herein, is defined to mean any liquid having a viscosity of greater
than about 100 cps and less than about 45,000 cps, measured at a
shear rate of 1/s at ambient temperature. Approximate diameter is
defined to mean the estimated diameter of a discrete particle that
is not a perfect sphere. Hydrophobically modified polycarboxylic
acid is defined to mean a compound, oligomer or polymer having at
least one carboxylic acid group and at least one group that is not
water soluble.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The materials that may be used to make the water soluble
sachets of this invention include those which may generally be
classified as water soluble resins, such as film-forming water
soluble resins, either organic or inorganic.
[0023] Suitable water-soluble resins which may be used in the
invention are described in Davidson and Sittig, Water-Soluble
Resins, Van Nostrand Reinhold Company, New York (1968), herein
incorporated by reference. The water-soluble resin should have
proper characteristics such as strength and pliability in order to
permit machine handling. Preferred water-soluble resins include
polyvinyl alcohol, cellulose ethers, polyethylene oxide, starch,
polyvinylpyrrolidone, polyacrylamide, polyvinyl methyl ether-maleic
anhydride, polymaleic anhydride, styrene maleic anhydride,
hydroxyethylcellulose, methylcellulose, polyethylene glycols,
carboxymethylcelulose, polyacrylic acid salts, alginates,
acrylamide copolymers, guar gum, casein, ethylene-maleic anhydride
resin series, polyethyleneimine, ethyl hydroxyethylcellulose, ethyl
methylcellulose, hydroxyethyl methylcellulose. Lower molecular
weight water-soluble, polyvinyl alcohol film-forming resins are
generally, preferred.
[0024] The generally preferred water-soluble, polyvinyl alcohol
film-forming resins should, in addition to low weight average
molecular weights, have low levels of hydrolysis in water.
Polyvinyl alcohols preferred for use herein have a weight average
molecular weight between about 1,000 and about 300,000, and
preferably, between about 2,000 and about 150,000, and most
preferably, between about 3,000 and about 100,000, including all
ranges subsumed therein.
[0025] Even further, it is within the scope of this invention to
include polyvinyl alcohol films which are copolymers such as films
prepared from vinyl acetate and methacrylic acid precursor
monomers. Preferred copolymers typically comprise less than about
15.0% by weight methacrylic acid units in their backbone.
[0026] When compared to plastics, the tensile strength of polyvinyl
alcohol is relatively high, and when compared with other
water-soluble materials, the tensile strength of polyvinyl alcohol
is extremely high. Reasonable tensile strength is required in film
used in sachets of the present invention in order to permit proper
handling and machining of the articles. The tensile strength of
polyvinyl alcohol will vary with a number of factors, including the
percent hydrolysis, degree of polymerization, plasticizer content,
and humidity. In a most preferred embodiment, polyvinyl alcohol is
used to make the water soluble sachet of this invention and the
dishwashing composition contained therein is substantially free of
an unencapsulated compound containing boron, whereby substantially
free is defined to mean less than about 2.0% by weight of boron
containing compound, based on total weight of the dishwashing
composition within the water soluble sachet.
[0027] Polyvinylpyrrolidone, another preferred resin for use to
make the sachets of the present invention, may be made from a
variety of solvents to produce films which are clear, glossy, and
reasonably hard at low humidities. Unmodified films of
polyvinylpyrrolidone may be hygroscopic in character. Tackiness at
higher humidities may be minimized by incorporating compatible,
water-insensitive modifiers into the polyvinylpyrrolidone film,
such as 10% of an aryl-sulfonamide-formaldehyde resin.
[0028] Other preferred water-soluble films may also be prepared
from polyethylene oxide resins by standard calendering, molding,
casting, extrusion and other conventional techniques. The
polyethylene oxide films may be clear or opaque, and are inherently
flexible, tough, and resistant to most oils and greases. These
polyethylene oxide resin films provide better solubility than other
water soluble plastics without sacrificing strength or toughness.
The excellent ability to lay flat, stiffness, and sealability of
water-soluble polyethylene oxide films make for good machine
handling characteristics.
[0029] The weight percent of water-soluble, film-forming resin in
the final articles of the present invention is from about 0.1% to
about 10%, preferably about 0.25% to about 7.5%, and most
preferably about 0.50% to about 5%, including all ranges subsumed
therein.
[0030] As to the dishwashing composition that may be used in this
invention, such a composition is a gel having a viscosity from
about 100 to about 45,000 cps, and preferably, from about 200 to
about 30,000 cps, and most preferably, from about 300 to about
25,000 cps, at ambient temperature, including all ranges subsumed
therein. The components of the dishwashing composition of this
invention are limited only to the extent that they may be combined
to make a gel having the above-described viscosities and that they
do not degrade the structural properties of the film sachet forming
materials to an extent where the dishwashing properties of the
dishwashing composition are compromised. Typically, such components
include water, thickening agent, bleach, buffering agent and
builder. Water typically makes up the balance. The dishwashing
composition within the water soluble sachet of the present
invention can comprise optional ingredients which include
colorants, bleach scavengers, perfumes, lime soap dispersants,
inert organic molecules, enzymes (liquid or solid),
enzyme-stabilizers, builders, surfactants, non-encapsulated bleach,
anti-foam, anti-tarnish and anti-corrosion agents.
[0031] In a preferred embodiment the dishwashing composition used
in this invention comprises: [0032] a) an anti-spotting agent
comprising a hydrophobically modified polycarboxylic acid, a
surfactant having a cloud point in water of less than about
60.degree. C., or both; and [0033] b) a water soluble polymer that
reduces phosphate scale formation, a compound that reduces
carbonate scale formation, or both wherein the dishwashing
composition is a gel.
[0034] There generally is no limitation with respect to the type of
hydrophobically modified polycarboxylic acid that may be used in
this invention other than that the polycarboxylic acid can be used
in a dishwashing composition that comprises a water soluble
polymer. Such a hydrophobically modified polycarboxylic acid often
has a weight average molecular weight of greater than about 175 and
less than about 1.5 million, and preferably, greater than about 200
and less than about 1 million; and most preferably, greater than
about 225 and less than about 750 thousand, including all ranges
subsumed therein.
[0035] The preferred hydrophobically modified polycarboxylic acid
which may be used in this invention comprises at least one
structural unit of the formula:
##STR00001##
wherein each R.sup.1 and R.sup.2 are independently a hydrogen,
hydroxy, alkoxy, carboxylic acid group, carboxylic acid salt, ester
group, amide group, aryl, C.sub.1-20 alkyl, C.sub.2-20 alkenyl,
C.sub.2-20 alkynyl or a polyoxyalkylene condensate of an aliphatic
group, n is an integer from about 0 to 8, z is an integer from
about 1 to about 8, t is an integer from about 0 to about 2,000 and
a is an integer from about 0 to about 2,000, with the proviso that
a and t are not simultaneously 0 and at least one R.sup.1 or one
R.sup.2 is a carboxylic acid group, or a salt thereof.
[0036] In a preferred embodiment, the hydrophobically modified
polycarboxylic acid used in this invention comprises at least one
structural unit represented by formula I (t-1) with at least one
R.sup.1 as a carboxylic acid group (or salt thereof), and at least
one structural unit represented by formula II (a-1) with at least
one R.sup.2 group as a C.sub.4-20 alkyl group or a C.sub.8-30
ethoxylated condensate of an aliphatic group.
[0037] In a most preferred embodiment, however, the modified
polycarboxylic acid used in this invention comprises structural
units represented by formula I and structural units represented by
formula II wherein a is from about 80% to about 120% of t, and at
least two R.sup.1 groups are carboxylic acid groups (or salts
thereof) and at least one R.sup.2 group is a methyl group and at
least one R.sup.2 group is a C.sub.5 alkyl, and n is 0 and z is
1.
[0038] The hydrophobically modified polycarboxylic acids which may
be used in this invention are typically prepared by reacting the
desired precursors (sp.sup.2 bonded monomers) under free radical
polymerization conditions. Such polycarboxcylic acids are also
commercially available from suppliers like Rohm & Haas and
DuPont. A more detailed description of the types of hydrophobically
modified polycarboxylic acids which may be used in this invention,
including the process for making the same, may be found in U.S.
Pat. No. 5,232,622, the disclosure of which is incorporated herein
by reference.
[0039] The preferred and most preferred hydrophobically modified
polycarboxylic acids are made available by Rohm & Haas under
the names Acusol 820 and 460, respectively.
[0040] There is generally no limitation with respect to how much
hydrophobically modified polycarboxylic acid that may be used in
this invention other than the amount used results in a dishwashing
composition. Typically, however, from about 0.1 to about 10.0, and
preferably, from about 0.2 to about 7.0, and most preferably, from
about 0.3 to about 5.0% by weight of the dishwashing composition is
a hydrophobically modified polycarboxylic acid, based on total
weight of the dishwashing composition, including all ranges
subsumed therein.
[0041] The surfactant having a cloud point in water of less than
about 60.degree. C. typically enhances wetting properties of the
glassware being cleaned. These nonionic surfactants can be broadly
defined as surface active compounds with at least one uncharged
hydrophilic substituent. A major class of nonionic surfactants are
those compounds produced by the condensation of alkylene oxide
groups with an organic hydrophobic material which may be aliphatic
or alkyl aromatic in nature. The length of the hydrophilic or
polyoxyalkylene radical which is condensed with any particular
hydrophobic group can be readily adjusted to yield a water-soluble
compound having the desired degree of balance between hydrophilic
and hydrophobic elements. Illustrative examples of various suitable
nonionic surfactant types are polyoxyalkylene condensates of
aliphatic carboxylic acids, whether linear- or branched-chain and
unsaturated or saturated, especially ethoxylated and/or
propoxylated aliphatic acids containing from about 8 to about 18
carbon atoms in the aliphatic chain and incorporating from about 2
to about 50 ethylene oxide and/or propylene oxide units. Suitable
carboxylic acids include "coconut" fatty acids (derived from
coconut oil) which contain an average of about 12 carbon atoms,
"tallow" fatty acids (derived from tallow-class fats) which contain
an average of about 18 carbon atoms, palmitic acid, myristic acid,
stearic acid and lauric acid.
[0042] Other nonionic surfactants having a cloud point of less than
about 60.degree. C. include polyoxyalkylene condensates of
aliphatic alcohols, whether linear- or branched-chain and
unsaturated or saturated, especially ethoxylated and/or
propoxylated aliphatic alcohols containing from about 6 to about 24
carbon atoms and incorporating from about 2 to about 50 ethylene
oxide and/or propylene oxide units. Suitable alcohols include
"coconut" fatty alcohol, "tallow" fatty alcohol, lauryl alcohol,
myristyl alcohol and oleyl alcohol. Preferred examples of such
materials are provided by BASF Corporation as a series under the
tradename Plurafac. Particularly preferred surfactants are Plurafac
LF 301, Plurafac LF 403 and Plurafac SLF-18. Also included within
this class of nonionic surfactants are epoxy capped
poly(oxyalkylated) alcohols as described in WO 94/22800. A
preferred example of this class of material is poly-tergent SLF 18B
45 made available by BASF Corporation.
[0043] Polyoxyethylene or polyoxypropylene condensates of alkyl
phenols, whether linear- or branched-chain and unsaturated or
saturated, containing from about 6 to 12 carbon atoms and
incorporating from about 2 to about 25 moles of ethylene oxide
and/or propylene oxide are other types of nonionic surfactants
which may be used.
[0044] Other desired nonionic surfactants which may be used include
polyoxyethylene-polyoxypropylene block copolymers having formulae
represented as
HO(CH.sub.2CH.sub.2O).sub.a(CH(CH.sub.3)CH.sub.2O).sub.b(CH.sub.2CH.sub.-
2O).sub.cH
or
HO(CH(CH.sub.3)CH.sub.2O).sub.d(CH.sub.2CH.sub.2O).sub.e(CH(CH.sub.3)CH.-
sub.2O).sub.fH
wherein a, b, c, d, e and f are integers from 1 to 350 reflecting
the respective polyethylene oxide and polypropylene oxide blocks of
said polymer. The polyoxyethylene components of the block polymer
constitutes at least about 10% of the block polymer. The material
preferably has a molecular weight of between about 1,000 and
15,000, more preferably from about 1,500 to about 6,000.
[0045] These materials are well known in the art. They are
available as a series of products under the trademark "Pluronic"
and "Pluronic R", from the BASF Corporation.
[0046] It is also noted herein that while the anti-spotting agents
used in this invention typically have a cloud point of less than
about 60.degree. C., they preferably have a cloud point of less
than about 50.degree. C., and most preferably, less than about
45.degree. C.
[0047] The surfactants having a cloud point in water of less than
about 60.degree. C. are typically present within the dishwashing
composition at levels of at least 0.5 wt. %, preferably, 1-15 wt.
%, and most preferably, 1.5 to 8 wt. %, based on the total weight
of the dishwashing composition, including all range subsumed
therein.
[0048] As to the water soluble polymer that reduces phosphate scale
formation, such a polymer often comprises at least one structural
unit derived from a monomer having the formula:
##STR00002##
[0049] wherein R.sup.3 is a group comprising at least one sp.sup.2
bond, z is O, N, P, S, or an amido or ester link, A is a mono- or a
polycyclic aromatic group or an aliphatic group and each p is
independently 0 or 1 and B.sup.+ is a monovalent cation.
[0050] Preferably, R.sup.3 is a C.sub.2 to C.sub.6 alkene (most
preferably ethene or propene). When R.sup.3 is ethenyl, Z is
preferably amido, A is preferably a divalent butyl group, each t is
1, and B.sup.+ is Na.sup.+. Such a monomer is polymerized and sold
as Acumer 3100 by Rohm & Haas.
[0051] Another preferred embodiment exists when the water soluble
polymer is derived from at least one monomer with R.sup.3 as
2-methyl-2-propenyl, Z as oxygen, A as phenylene, each t as 1 and
B.sup.+ as Na.sup.+, and at least one monomer with R.sup.3 as
2-methyl-2-propenyl, each t as 0 and B.sup.+ as Na.sup.+. Such
monomers are polymerized and sold under the name Alcosperse 240 by
Alco Chemical.
[0052] It is further noted herein that it is within the scope of
this invention for all the polymers used to be a homopolymer or
copolymer, including terpolymers. Furthermore, the polymers of this
invention may be terminated with conventional termination groups
resulting from precursor monomers and/or initiators that are
used.
[0053] There is generally no limitation with respect to how much
water soluble polymer that reduces phosphate scale formation is
used in this invention as long as the amount used results in a
dishwashing composition. Often, from about 0.5 to about 10.0, and
preferably, from about 1.0 to 7.0, and most preferably, from about
1.5 to about 4.5% by weight water soluble polymer is used, based on
total weight of the dishwashing composition, including all ranges
subsumed therein. These water soluble polymers typically have a
weight average molecular weight from about 1,000 to about
50,000.
[0054] Regarding the compounds that may be used to reduce carbonate
scale formation, these include polyacrylates (and copolymers
thereof) having a weight average molecular weight from about 1,000
to about 400,000. Such compounds are supplied by Rohm and Haas,
BASF, and Alco Corp. Preferred copolymers include those derived
from acrylic acid and maleic acid monomers like Sokalan CP5 and CP7
supplied by BASF, and Acusol 479N, supplied by Rohm & Haas.
Copolymers of acrylic acid and methacrylic acid (Colloid 226/35),
as supplied by Rhone-Poulenc, may also be used.
[0055] Other materials that may be used to reduce carbonate scale
formation include phosphonate functionalized acrylic acid (Casi 773
as supplied by Buckman laboratories); copolymers of maleic acid and
vinyl acetate, and terpolymers of maleic acid, acrylic acid and
vinyl acetate (made commercially by Huts); polymaleates (like
Belclene 200, as supplied by FMC); polymethacrylates, (like Tomal
850, as supplied by Rohm & Haas); polyaspartates; ethylene
diamine disuccinate, organopolyphosphonic acids (and salts thereof)
such as sodium salts of amino tri(methylenephosphonic acid),
diethylene triamine penta (methylene phosphonic acid);
hexamethylene diamine tetramethylene phosphonic acid; ethane
1-hydroxy-1,1-diphosphonic acid (HEDP); organomonophosphonic acids
(and salts thereof) such as the sodium salt of
2-phosphono-1,2,4-butane tricarboxylic acid, all of which are sold
under the Dequest line as supplied by Solutia. Phosphates,
especially alkali metal tripolyphosphates may also be used as well
as mixtures of the above-described materials. It has also been
found that combinations of anti-scaling agents can be more
effective at reducing calcium carbonate scale than individual
anti-scaling agents themselves.
[0056] The materials that may be used to reduce carbonate scale
formation typically make up from about 0.01% to about 10.0%, and
preferably, from about 0.1% to about 6.0%, and most preferably,
from about 0.2% to about 5.0% by weight of the total weight of
dishwashing composition, including all ranges subsumed therein.
[0057] Any conventional dishwashing builders may be used in this
invention. Non-phosphate containing builders such as alkali metal
salts of polycarboxylic acids may be sued (e.g., sodium citrate,
iminodisuccinate, oxydisuccinate). Phosphate containing builders
are a preferred builder in this invention. Such builders typically
make up from about 5.0 to about 75.0% by weight of the total weight
of the dishwashing composition, including all ranges subsumed
therein. Preferably, however, the amount of phosphate containing
builder employed is from about 10.0 to about 70.0, and most
preferably, from about 15.0 to about 65.0% by weight based on total
weight of the dishwashing composition and including all ranges
subsumed therein. The phosphate containing builders which may be
used in this invention are well known, for example, for binding
metals such as Ca and Mg ions, both of which are often abundant in
hard water found in dishwashing machines. An illustrative list of
the phosphate builders which may be used in this invention include
sodium, potassium and ammonium pyrophosphate; alkali metal
tripolyphosphates, sodium and potassium orthophosphate and sodium
polymetaphosphate, with potassium tripolyphosphate (KTP) being
especially preferred.
[0058] As to the discrete particles that enhance cleaning in a
dishwashing machine, such particles, again, have an approximate
diameter from about 100 to about 5,000 microns, and preferably,
from about 200 to about 4,500 microns, and most preferably, from
about 300 to about 3,500 microns, including all ranges subsumed
therein.
[0059] When the discrete particle is an encapsulated bleach which
may be used in this invention, such a bleach (i.e., the core of the
encapsulated bleach) includes organic and inorganic peracids as
well as salts thereof. Illustrative examples include epsilon
phthalimido perhexanoic acid (PAP) and Oxone.RTM., respectively.
The bleaches may be employed with bleach activators, and
collectively, the bleach and the activator make up from about 0.02
wt. % to about 20.0 wt. % of the total weight of the dishwashing
composition.
[0060] The clad (i.e., outer shell) of the discrete particle which
is an encapsulated bleach is typically a wax such as a paraffin
wax. Such paraffin waxes have low melting points, i.e., between
about 40.degree. C. and about 50.degree. C. and a solids content of
from about 35 to 100% at 40.degree. C. and a solids content of from
0 to about 15% at 50.degree. C. This melting point range for the
clad material is desirable for several reasons. The minimum of
40.degree. C. generally exceeds any typical storage temperatures
that are encountered by cleaning compositions. Thus, the wax coat
will protect the core throughout storage of the cleaning
composition. The 50.degree. C. melting point cap for the wax clad
was selected as providing a wax which will quickly melt or soften
early in any automatic dishwashing wash cycle. Melting or softening
sufficient to release the core will occur because operating
temperatures in automatic dishwashers are usually between
40.degree. C. and 70.degree. C. Thus, the paraffin waxes of the
invention will release the core material when the capsule is
exposed to the warmed wash bath, but not before. Paraffin waxes are
selected over natural waxes for the subject invention because in
liquid alkaline environments, natural waxes hydrolyze and are
unstable. Moreover, melted paraffin waxes of the encapsulated
bleaches used in the invention will remain substantially molten at
40.degree.-50.degree. C. Such molten wax is easily emulsified by
surfactant elements in cleaning compositions. Consequently, such
waxes will leave less undesirable waxy residue on items to be
cleaned than waxes with higher melting points.
[0061] Thus, the wax coat preferably does not include any paraffins
having a melting point substantially above 50.degree. C., lest the
higher melting point components remain solid throughout the wash
cycle and form unsightly residues on surfaces to be cleaned nor any
paraffins with solid contents discussed below.
[0062] The distribution of solids of the paraffin waxes of the
invention ensures storage integrity of the encapsulated particles
at temperatures up to 40.degree. C. in either a liquid or moist
environment while yielding good melting performance to release its
active core during use at temperatures of about 50.degree. C.
[0063] The amount of solids in a wax at any given temperature as
well as the melting point range may be determined by measuring the
latent heat of fusion of each wax by using Differential Scanning
Calorimetry (DSC) by a process described in Miller, W. J. et al.
Journal of American Oil Chemists' Society, July, 1969, V. 46, No.
7, pages 341-343, incorporated by reference. This procedure was
modified as discussed below. DSC equipment used in the procedure is
preferably the Perkin Elmer Thermoanalysis System 7 or the Dupont
Instruments DSC 2910.
[0064] Specifically, the DSC is utilized to measure the total
latent heat of fusion of multi-component systems which do not have
a distinct melting point, but rather, melt over a temperature
range. At an intermediate temperature within this range one is
capable of determining the fraction of the latent heat required to
reach that temperature. When acquired for a multi-component mixture
of similar components such as commercial waxes, this fraction
correlates directly to the liquid fraction of the mixture at that
temperature. The solids fraction for the waxes of interest are then
measured at 40.degree. C. and 50.degree. C. by running a DSC trace
from -10.degree. C. to 70.degree. C. and measuring the fraction of
the total latent heat of fusion required to reach these
temperatures. A very low temperature ramping rate of 1.degree.
C./min should be used in the test to ensure that no shifting of the
graph occurs due to temperature gradients within the sample.
[0065] The more solids present in a wax at room temperature, the
more suitable the wax is for the present invention; this is because
such solids strengthen the wax coating, rendering the particle less
vulnerable to ambient moisture or a liquid aqueous environment,
whereas "oil" or liquid wax softens the wax, opening up pores in
the coating and thereby provides poorer protection for the core of
the particle. Significant solid paraffin remaining at 50.degree. C.
may remain on the cleaned hard surfaces (e.g., dishware in an
automatic dishwashing machine) and is undesirable.
[0066] Therefore, the wax solids content as measured by
Differential Scanning Calorimetry for suitable paraffin waxes may
range from 100 to about 35%, optimally from 100 to about 70%, at
40.degree. C. and from 0 to about 15% and preferably 0 to about 5%
at 50.degree. C.
[0067] Particles coated with micro-crystalline waxes would
therefore have a poorer protective coating, and the wax coat which
melts from such particles wold be less likely to emulsify in
cleaning compositions. Thus, micro-crystalline wax are not
considered within the operative scope of this invention.
[0068] Commercially available paraffin waxes which are suitable for
encapsulating the solid core materials include Merck 7150 (54%
solids content at 40.degree. C. and 2% solids content at 50.degree.
C.) ex. E. Merck of Darmstadt, Germany; IGI 1397 (74% solids
content at 40.degree. C. and 0% solids content at 50.degree. C.)
and IGI 1538 (79% solids content at 40.degree. C. and 0.1% solids
content at 50.degree. C. ex. The International Group, Inc. of
Wayne, Pa.; and Ross fully refined paraffin wax 115/120 (36% solids
content at 40.degree. C. and 0% solids content at 50.degree. C.) ex
Frank D. Ross Co., Inc. of Jersey City, N.J. Most preferred is IGI
1397.
[0069] Mixtures of paraffin waxes with other organic materials such
as polyvinyl ethers as described in U.S. Pat. Nos. 5,460,743 and
5,589,267 are also useful to make the clods of this invention.
[0070] Other bleaches which may be used within the discrete
particles (encapsulated bleaches) in this invention include
hydrogen peroxide and its precursors (e.g., sodium perborate and
sodium percarbonate), alkyl, aryl and acyl peroxides such as
benzoyl peroxide and solid chlorine bleach sources such as
dichloroisocyanurate.
[0071] When preparing the discrete particles which are encapsulated
bleaches, such an encapsulated particle is made via well known art
recognized techniques which include spraying molten wax onto bleach
particles in a fluidized bed. A preferred process is described in
U.S. Pat. No. 5,230,822. An encapsulated bleach (in the form of a
discrete particle) is preferred in this invention since the clad
prevents interactions between the bleach and film forming resin
during storage of the sachets.
[0072] If desired, conventional bleach activators (including
catalysts) may be used with the bleaches described herein. These
activators include (6-nonamidocaproxyl) oxybenzene sulfonate (as
described in EPO 170,386) N,N,N',N'-tetraacetylethylenediamine,
nonanoyloxybenzenesulfonate, cationic nitriles,
cholyl(4-sulfophenyl)carbonate, and quaternary imine salts (e.g.,
N-methyl-3,4-dihydrooisoquinolinium p-toluenesulfonate).
[0073] Other bleach activators which may be used include transition
metal-containing bleach catalysts such as [Mn.sup.IV
.sub.2(.mu.-0).sub.3(Me.sub.3TACN).sub.2](PF.sub.6).sub.2 (as
described in U.S. Pat. Nos. 4,728,455, 5,114,606, 5,153,161,
5,194,416, 5,227,084, 5,244,594, 5,246,612, 5,246,621, 5,256,779,
5,274,147, 5,280,117), [Fe.sup.II(MeN4py)(MeCN)](ClO.sub.4).sub.2
(as described in EP 0 909 809) and
[Co.sup.III(NH.sub.3).sub.5(OAc)](OAc).sub.2 (as described in U.S.
Pat. No. 5,559,261, WO 96/23859, WO 96/23860, WO 96/23861). It is
further noted that the bleach activators employable in this
invention may be added to the dishwashing composition as granulates
or encapsulated granulates or both.
[0074] It is also within the scope of this invention to employ
(optionally) discrete particles which are dishwashing enzymes. The
discrete particles which are enzymes typically make up from about
0.5 to about 10.0% by weight of the total weight of the dishwashing
composition and include proteases like Savinase.RTM., Purafect
Ox.RTM., Properase.RTM., and Ovozyme.RTM. and amylases like
Termamyl.RTM., Purastar ST.RTM., Purastar Ox Am.RTM., and
Duramyl.RTM., all of which are commercially available.
[0075] Other discrete particles which may be used in this invention
include those comprising an antifoaming agent. These discrete
particles may comprise essentially any known antifoam compound,
including, for example, silicone antifoams, silicone oil, mono- and
distearyl acid phosphates, mineral oil, and 2-alkyl and alcanol
antifoam compounds. These antifoaming agents may be used in
combination with defoaming surfactants. The dishwashing composition
typically comprises from about 0.02 to 2% by weight of antifoaming
agent in the form of a discrete particle, preferably, 0.05 to
1.0%.
[0076] Other discrete particles which may be used in the water
soluble sachets of this invention include anti-tarnishing agents.
Such anti-tarnishing agents typically comprise benzotriazole, 1,3
N-azoles, isocyanuric acid, purine compounds, and mixtures
thereof.
[0077] The buffering agents which may be used typically make up
from about 1.0 to about 25.0% by weight of the total weight of the
dishwashing composition and include well known buffering agents
like potassium and sodium salts of disilicate, bicarbonate and
carbonate. Conventional dishwashing surfactants may also
(optionally) be employed in this invention and these include
anionic surfactants like alkyl sulfates and sulfonates as well as
fatty acid ester sulfonates. Particularly, salts of (i.e., sodium,
potassium, ammonium, and substituted ammonium salts such as mono-,
di- and triethanolamine salts) anionic sulfates, sulfonates,
carboxylates, and sarcosinates may be used. Other optional anionic
surfactants which may be used include isothionates, like
acyl-isothionates, N-acyltaurates, fatty acid amides of methyl
tauride, alkyl succinates and sulfocsuccinates; mono esters of
sulfosuccinate; and diesters of sulfosuccinate. These types of
surfactants often make up from about 0.0% to about 10.0% by weight
of the total weight of the dishwashing composition.
[0078] When preparing the dishwashing composition of this
invention, the desired components (e.g., anti-spotting agent and
water soluble polymer) or solutions thereof are mixed, and added to
a solution of the thickening agent. The order of addition of
ingredients can be varied. The amount of water present in the
detergent composition is typically from about 15% to about 80%, and
preferably from about 20% to about 75% and most preferably from
about 25% to about 70% by weight, based on total weight of the
detergent composition, including all ranges subsumed therein. The
thickeners which may be used in this invention include cross-linked
anionic polymers. Illustrative examples include cross-linked
polyacrylic acid-type thickening agents which are sold by B.F.
Goodrich under their Carbopol trademark. Especially preferred are
Carbopol 934, 940, 941, 980 and 981.
[0079] The amount of the high molecular weight, cross-linked
polyacrylic acid or other high molecular weight, hydrophilic
cross-linked polyacrylic acid-type thickening agent to impart the
desired rheological property of linear viscoelasticity will
generally be in the range of from about 0.1 to 3.0%, and
preferably, from about 0.2 to 2.0% by weight based on the weight of
the composition. It is also noted that thickening agents that are
not bleach resistant may also be employed with the sachets of the
present invention.
[0080] Other optional additives which may be used with the
preferred embodiments of this invention include well known items
such as perfumes, dispersants, colorants, lime soap dispersants,
inert organic molecules, enzyme stabilizers, non-encapsulated
bleaches and bleach scavengers. Such additives, collectively, do
not normally make up more than about 8.0% by weight of the total
weight of the dishwashing composition.
[0081] When washing glassware with the dishwashing composition of
this invention, soiled glassware is typically placed in a
conventional domestic or commercial dishwashing machine as is the
dishwashing composition of this invention (in no particular order).
The dishwashing composition of this invention then dissolves in the
water (as does the sachet comprising it) of the dishwasher to wash
the glassware. The typical dishwashing cycle is from about 10
minutes until about 60 minutes and the typical temperature of the
water in the dishwasher is from about 40.degree. C. to about
70.degree. C. The glassware resulting from the above-described
cleaning method is clean and has an excellent glass appearance
(i.e., substantially free of film and spots). Such results are
unexpectedly obtained even when hard water at high temperatures
(greater than 55.degree. C.) is used, in the absence of rinse aid
compositions.
[0082] When marketing the superior dishwashing composition having
the discrete particle of this invention, it is preferred that the
dishwashing composition is a gel, as described above, and sold in a
package with directions to add the dishwashing composition to the
dishwashing machine as a 3-in-1 product. Thus, a dishwasher is
charged with the dishwashing composition of this invention without
having to add to the dishwasher conventional rinse aid compositions
and sodium chloride.
[0083] When preparing the actual water soluble sachets of the
present invention, any of the art recognized techniques for making
water soluble sachets may be used.
[0084] One particularly preferred method for pressing the actual
water soluble sachets of the present invention employ thermoformed
packages. The thermoforming process generally involves molding a
first sheet of water soluble film to form one or more recesses
adapted to retain the gel of the current invention, placing the gel
in at least one recess, placing a second sheet of water soluble
material over the first so as to cover each recess, and heat
sealing the first and second sheets together at least around the
recesses so as to form one or more water soluble packages, as
described in WO 00/55415. A second route comprises vertical
form-fill-seal (VFFS) envelopes. In one of the VFFS processes, a
roll of water soluble film is sealed along its edges to form a
tube, which tube is heat sealed intermittently along its length to
form individual envelopes which are filled with gel and heat
sealed.
[0085] The size and the shape of the sachet are not limited and
individual sachets may be connected via perforated resin.
Preferably, the sachet is of the size to carry a unit dose for a
domestic dishwashing machine.
[0086] The following examples are proved to facilitate an
understanding of the present inventions. The examples are not
intended to limit the scope of the inventions as described in the
claims.
TABLE-US-00001 Examples 1 2 3 4 5 6 7 8 Carbopol 627 1.5 Carbopol
980 1 0.8 1.5 1.5 1.5 Carbopol 941 1 KTP 30 31 27.4 29 30 28 30
40.8 Potasium 8 carbonate Potasium 7.6 8 bicarbonate Glycerol 6 6.8
6 6 7.5 7.5 6 11.5 KOH 0.8 0.7 0.6 0.6 0.8 0.8 1.1 Sokalan CP7 5
Sokalan PA25 3.8 3.4 3.7 3.7 3.7 5.6 PN Na EHDP 0.8 0.7 0.8 0.8 1.1
0.8 0.9 Sodium 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 sulfite Nonionic 2
2.1 1.9 4.5 2 4 2 2.3 surfactant.sup.a Bleach (PAP 4.3 4.6 9.2 4.3
4.3 4.3 4.3 4.2 capsules) Amylase 0.4 0.7 0.7 0.4 0.4 0.4 0.4 0.6
Protease 0.6 1.6 1.6 0.6 0.6 0.6 0.6 1.5 Alcosperse 240 2 2 2 2.8
Acusol 460 2 1 1 1 SLS 1.4 1.2 2 1.7 Antifoam 1.6 1.5 0.6 1.5
.sup.aNonionic surfactant used was Plurafac LF 403 or Poly-Tergent
SLF-18B 45.
[0087] Examples 1-8 depict examples of detergent compositions with
discrete particles that included encapsulated bleaches, enzymes and
anti-foams all of which was filled into the sachets in the
described inventions. All sachets were made with PVA film (Chris
Craft M8630).
Example 9
[0088] Cleaning experiments were carried out in Bauknecht
dishwasher using the 50 BIO(N) program. Detergent, 33 grams, as
described in example 3, was sealed within a sachet. The pouch was
placed in the dispenser of the machine. Water used for the
experiment was adjusted to 300 ppm permanent hardness with
Ca:Mg=4:1 and NaHCO.sub.3 adjusted to 320 ppm. Soils used included:
4 ceramic plates coated with 2.0 g egg yolk on each plate; 4
stainless steel plates coated with 2.0 g each of egg yolk; 4
ceramic plates coated with 2.0 g ea. of potato starch soil; 4
ceramic plates coated with 2.0 g ea. of cream of wheat; 4 ceramic
plates coated with 2.0 g ea. of roux soil; 40 g of ASTM butter-milk
soil; 6 cups with 3.times. tea stain. 8 clean glasses were placed
onto the top rack of dishwasher. Teacups were visually assessed for
residual tea stain and scored on a scale of 0-5 with a score of 0
indicating 100% clean 5 representing unwashed cups. The egg plates
were visually examined for residual soil, and were then scored on a
scale from 0 (no residual soil) to 100 (100% area covered with
soil), while wheat and roux plates were dipped in an iodine bath to
expose residual soil and scored on a 0-100 scale similar to the egg
soil. The scores reported in example 10 are average scores of each
type of soil.
TABLE-US-00002 Example 9 Tea Egg-Ceramic Egg-Steel Wheat Roux Score
2.1 0 0 0 10
[0089] As can be seen by example 9, the dishwashing gel composition
with discrete particle for enhancing cleaning in a dishwasher
enclosed in a water soluble sachet provided excellent cleaning
results.
Examples 10-12
[0090] Tests to monitor the anti-spotting and anti-filming efficacy
of formulations were performed in a Miele G656 machine, using a
55.degree. C. Normal cleaning cycle. Water used for the experiment
was adjusted to 300 ppm permanent hardness with Ca:Mg=4:1 and
NaHCO.sub.3 adjusted to 320 ppm. 40 g of buttermilk soil on the
door of the dishwasher and 10 g of egg yolk were added prior to the
run. A full clean dish load, with 8 glasses, was included for
scoring. At the end of the run, glasses were scored for spotting.
Spotting scores were recorded based on area covered by, and
intensity of the spots. The scores are expressed on a 0 to 5 scale,
0 being completely free of spots. The sachets containing 33 g of
formulation (made per example 1) were dosed via the dispenser and
the polymer additives were dosed as either aqueous solutions
(Example 11) or as solids (Example 12) at the time of cup
opening.
TABLE-US-00003 Example Dose Spots 10 1 sachet 1.4 11 1 pouch + 0.8
2.16 g Acusol 460(25% active) + 1.23 g Alcosperse 240 (44% active)
12 1 pouch + 2.5 0.54 g Acusol 460 (solid) + 0.54 g Alcosperse
240-D (solid)
[0091] As can be seen by a comparison of Examples 12 and 13 there
is a significant performance advantage when the polymers are dosed
in the liquid form rather than as dried solids.
* * * * *